Introduction to the study of inorganic chemistry / by William Allen Miller.

  • Miller, William Allen, 1817-1870.
Date:
1871
Catalogue details

Licence: Public Domain Mark

Credit: Introduction to the study of inorganic chemistry / by William Allen Miller. Source: Wellcome Collection.

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    copper pyrites (CujS, Fc2S3); and other less common ores are the green carbonate, malachite (CuCOa, CuO, HjO), and the blue carbonate (2C11CO3, CuO, H^O). In the WeLsh process of copper smelting, the pyrites is roasted at a dull red heat, to get rid of portions of the sul- jihur. The calcined ore is then melted with a siliceous slag, which removes the iron in the form of silicate of the oxide, leaving the copper in the, condition of a heavy fusible sub- sulphide. This is se])arated from the slag, which floats above it, and is then roasted, so as partly to get rid of the sulphur as sulphurous anhydride, and i)artly to convert the copper into oxide. When this ])oint is reached, the smelter stirs in this oxide, and mixes it with undecomposed cupreous sulphide. The copper, both from the oxide and the sulphide, then becomes reduced to the metallic state, and the sulphur and oxygen pass off together as sulphurous anhydride— • CiuS + 2Cu() — 4C11 4- SCT. The crude or blistered copper thus obtained is then melted in large quantities in a reverberatory furnace, where it is poled', that is to say, the trunk of a young tree is thrust into the melted metal, and thus the last portions of oxide arc reduced to the metallic state by the combustible gases given off by the wood, and the co])per is brought into the pure and tough condition in which it is required for use. Copper is a tough, tenacious, and .somewhat hard metal, with a well-known red colour. It emits a ])eculiar odour when rubbed. It may be drawn into very fine wire, can be rolled into foil, and hammered into leaf. It is an excellent conductor of electricity and of heat. When recpiired in a state of perfect purity, it may readily be deposited in sheets from a .solution of its sulphate by the current from one or two cells of the voltaic battery. It tarnishes when exposed to the atmosphere ; and if heated to redness in the air, a layer of oxide is formed upon the surface, which scales off if it be suddenly quenched in water, leaving the metal bright beneath.